Dynamics AX 2012 Only One Copy of a Form Open - forms

Question

Anyone have any tips/code snippets for preventing more than one copy of a custom X++ form from being opened at a time?
Best case: Attempt to open another copy of the form, and the original gains focus
Acceptable: User receives a notice that the form is already open

Answer 1

you could insert the code below into the form's init method.
If you have any questions to the code don't hesitate to ask!
public void init()
{
#define.CACHE_OWNER ('MyForm')
#define.CACHE_KEY_INSTANCE ('Instance')
FormRun existingForm()
{
;
if (infolog.globalCache().isSet(#CACHE_OWNER, #CACHE_KEY_INSTANCE))
{
return infolog.globalCache().get(
#CACHE_OWNER, #CACHE_KEY_INSTANCE);
}
return null;
}
void registerThisForm()
{
;
infolog.globalCache().set(#CACHE_OWNER, #CACHE_KEY_INSTANCE, this);
}
boolean isAlreadyOpened()
{
;
return existingForm() ? !existingForm().closed() : false;
}
void activateExistingForm()
{
;
existingForm().activate(true);
}
;
super();
if (isAlreadyOpened())
{
activateExistingForm();
this.close();
}
else
{
registerThisForm();
}
}

Answer 2

Add the following code to the init method of the form as follows. No other changes are required.
public void init()
{
#define.CACHE_OWNER('MyForm')
int hWnd;
super();
if (infolog.globalCache().isSet(#CACHE_OWNER, curUserId()))
{
hWnd = infolog.globalCache().get(#CACHE_OWNER, curUserId());
}
if (WinApi::isWindow(hWnd))
{
element.closeCancel();
WinAPI::bringWindowToTop(hWnd);
}
else
{
infolog.globalCache().set(#CACHE_OWNER, curUserId(), element.hWnd());
}
}